JCRS highlights selected by Professor Thomas Kohnen

CXL INNOVATION Contact lens-assisted corneal crosslinking (CXL), which uses a riboflavin-soaked UV barrier-free contact lens placed on a de-epithelised cornea before UVA exposure, is a relatively new technique. The objective is to artificially increase the functional thickness or to artificially decrease the effective UVA irradiation of the corneal stroma during the crosslinking procedure. The demarcation line is used as a surrogate measure of the depth and effectiveness of crosslinking. Researchers conducted a small clinical study looking at the demarcation line depth after contact lens-assisted CXL for progressive keratoconus comparing dextran-based and hydroxypropyl methylcellulose (HPMC)-based riboflavin solutions. CXL performed using riboflavin 0.1% combined with HPMC as the carrier agent resulted in a significantly deeper demarcation line than when the procedure was performed with dextran 20.0%-based riboflavin. C Malhotra et al., JCRS, “Demarcation line depth after contact lens-assisted corneal crosslinking for progressive keratoconus: Comparison of dextran-based and hydroxypropyl methylcellulose-based riboflavin solutions”, Volume 43, Issue 10, 1263–1270. PINHOLE IMPLANT FOR ASTIGMATISM Irregular corneal astigmatism from causes including keratoconus, post-radial keratotomy, post-penetrating keratoplasty and traumatic corneal laceration impairs visual function. Brazilian researchers report a case series of 21 patients treated with a novel pinhole implant. The device is a black opaque diaphragm with a 1.3mm central opening and no refractive power. It is designed to be implanted in the ciliary sulcus of pseudophakic eyes in a piggyback configuration. Patients receiving the implant had statistically significant improvement in uncorrected and corrected distance visual acuities. No major complications occurred. CC Trindade et al., JCRS, “New pinhole sulcus implant for the correction of irregular corneal astigmatism”, Volume 43, Issue 10, p1297–1306. POST-OP FALLS AFTER CATARACT SURGERY While cataract surgery has been shown to reduce the incidence of falls in elderly patients, post-op falls still do occur. A prospective cohort study conducted at eight public hospital eye clinics in Australia looked at 196 patients that completed first-eye surgery. First-eye cataract surgery reduced incident falls by 33%. Poorer dominant-eye visual acuity was associated with falls during the study timeline. Patients with larger than a spherical equivalent of ±0.75 dioptre change in the spectacle lens (operated eye) had a twofold greater incidence of falls in the period after first-eye cataract surgery than those with less or no change in lens power. The increased risk linked to major changes in the dioptric power of spectacle correction of the operated eye after surgery suggests that cautious postoperative refractive management is important. A Palagyi et al. JCRS, “Visual and refractive associations with falls after first-eye cataract surgery”, Volume 43, Issue 10, p1313–1321.